Abstract
The author carried out an experiment to find out the response of cat shark, Scyliorhinus torazame(Tanaka) to the colored lights. The experimental thank (360L$\times$50W$\times$55H cm) was set up in a dark room. Six longitudinal sections with 60cm intervals are marked in the tank to observe th location of the fish. Water depth in the tank was kept 50cm level. Light bulbs of 20W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The favorite color of the fish was found in the order of yellow, white, blue and red in day time, and red, blue, white and yellow at night time. The variation of the gathering rate on illumination time was very little and showed more stability in day time than at night time. The differences of the gathering rates to two selected colors out of the four colors were greater regardless of illumination time.
색광에 대한 두툽상어 Scyliorhinus torazame의 행동을 조사하기 위하여, 2가지 서로 다른 색광을 조합하여 수조의 양단에서 동시에 광자극을 가했을 때의 반응을 조사한 결과는 다음과 같다. 1. 수조내에서의 구간별 분포곡선은 대체로 W자형이 되었다. 2. 양색광원쪽에서의 평균분포차는 10.19%(0.17~25.75%)였고, 주간(6.72%)보다 야간(13.66%)에 더 컸다. 3. 두툽상어가 잘 모이는 색광은 주간에는 황색, 백색, 청색, 적색의 순이며, 야간에는 적색, 청색, 백색, 황색의 순으로 나타났다. 4. 조명시간의 경과에 따른 집어율의 변화는 적었으며 비교적 안정하게 변동했는데 주간에 더 안정되었다. 5. 두 가지 색광에 대한 집어율의 차는 조명시간에 관계없이 대체로 뚜렷했는데 주간보다 야간에 더 차가 심했다